lamme



(No Model.)

B G LAMME DYNAMO ELECTRIC GENERATOR.

No. 561,593. Patented June 9, 1896.

UNITED STATES PATENT OFFICE.

BENJAMIN G. LAMME, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO TIIE IVESTINGIIOUSE ELECTRIC AND MANUFACTURING COMPANY, OF SAME PLACE.

DYNAMO-ELECTRIC GENERATOR.

SPECIFICATION forming part of Letters Patent No. 561,593, dated June 9, 1896. Application filed September 4, 1895 Serial No. 561,409. (No model.)

To all whom it. may concern.- two sets of armature-coils are connected to- Be it known that I, BENJAMIN G. LAMME, a gether in series. The commutator-brushes citizen of the United States, residing in Pittshave sufficient surface contact with reference burg, in the county of Allegheny and State of to the spaces between the commutator-seg- 3 Pennsylvania, have inventedanew and usements to throw the two pairs of armature- 5 ful Improvement in Dynamo-Electric Genercoils in each set in parallel before the pair apators, (Case No. 665,) of which the following preaching zero electromotive force is commuis a specification. tated. This arrangement is such as to per My invention relates to dynamo-electric mit the pair of coils having a rising electrogenerators, andmoreparticularlytothat class motive force to drive back through the one of gen crators which is employed forsupplyin g having a falling elcctromotive force, and thus constant current to arc-light circuits. overcome the discharge and assist materially The object of my invention is to provide a in the commutation. The ampere-turns on machine of this class which shall readily acthe armature of a machine of this character 15 commodate itself to varying loads and operare necessarily very great as compared with ate efficiently without any shifting of the thetrue magnetizing powerof the field, and as commutatonbrushes or the employment of a consequence the large armature reaction reother external means of regulation. sults in the production of a lead which is at all My invention is illustrated in the accomtimesvery nearly ninetydegrees. Suchbeing 2o panying drawings, in whichthe case, a change of ordinary amount in the 79 Figure 1 is an end elevation of the dynamo, load cannot materially change the lead. Conand Fig. 2 is a diagram of the armature and sequently the point of commutation does not commutator-circuits. shift to any considerable extent, and auto- Referring to the drawings in detail, 1 is the matic shifting of the brushes is unnecessary.

25 field-magnet frame, provided with six radi- By reason of the fact that the lead is very ally-arranged pole-pieces 2, wound with ennearly ninety degrees, as has already been ergiZing-coils 3, which receive current from a stated, the armature-coils exert a very strong separate exciter 4c. The armature 5 is proreaction against the field. Such being the vided with two sets of coils 6 (Sand 7 7, case, irregularities or pulsations in the arma- 0 wound upon radial pole-pieces 8, which are ture-coils are liable to affect the field magprovided with enlarged heads or ends 9 at netization and cause interaction between the their outer extremities. The armature-coils circuits. In order to remedy this defect,I proare arranged in pairs, as is clearly shown in pose to provide the field-1nagnet pole-pieces Fig. 2, the two coils of each pair being wound with closed circuits 16 of definite resistance.

5 upon diametrically opposite poles and con- These closed circuits carry secondary curnected in series. The pairs 6 (5 and 6 6 are rents, the phase relations of which are fixed arranged at right angles to each other and to a considerable extent by their resistance. connected to the segments of the commutator- It is necessary, therefore, in constructing the cylinder 10, and the pairs 7 '7 and 7 7 are armachine to adjust the resistance of these 0 ranged in the same manner and alternating closed circuits until the secondary currents 0 with the first set and connected to the seghave such phase relations as to diminish the ments of the commutatoncylinder 11. Each armature reactions to the maximum practica of the commutator-cylinders 10 and 11 is proble degree. vided with twice as many segments as the \Vhile I have described a machine having 5 field-magnet has poles, the number in the afield-magnet and armature provided witha 5 present instance being twelve. The commuspecific number of coils, I desire it to be untator-cylinder 10 is provided with brushes 12 derstood that the invention is not limited to and 13 and the cylinder 11 with a correspondthis number or to the exact form and arrangeing pair of brushes 1a and 15, the brushes12 ment of the various parts.

50 and libeing connected as shown, so that the I claim as my invention :00

1. A dynamo-electric machine having a separately-excited field-magnet provided with auxiliary closed circuits, in combination with an armature having four pairs of coils arranged in two sets, the two pairs of each set being arranged at right angles to each other, a commutator for each set of armature-coils having twice as many segments as the machine has field-magnet poles, said commutators serving to connect the two sets of armature-coils in series. 7

2. In a direct-current arc-light dynamo, two commutators and two sets of armature-coils arranged in pairs, the pairs of each set being at right angles to each other, and the two sets being connected in series through the commutators.

3. In an arc-light dynamo, the combination with a separately-excited multipolar fieldmagnet and two commutators, of a radial-pole armature provided with two sets of coils arranged in pai *s, those of one set being respectively connected in series with those of the other set through the two commutators, and the pairs of each set being connected in parallel when the one approaching zero electromotive force is commutated.

4. In an arc-light dynamo, the combination with a multipolar separately-excited fieldmagnet and two commutators the cylinders of which have twice as many segments as the field-magnet has poles and the brushes of which bridge adjacent segments, of an armature having two alternately-arranged sets of coils, those of one set being respectively connectcd in series with the other through the two commutators.

5. In an arc-light dynamo, the combination with a six-pole field-magnet, of two commutators each having twelve segments, and a radial-pole armature having four pairs of coils in two alternately-arranged sets, the pairs of each set being respectively connected in series with those of the other through the commutators.

6. In an arc-light dynamo, the combination with a separately-excited field-magnet provided with regulating closed circuits, of two commutators and an armature provided with two sets of coils, those of one set being respectively connected in series with those of the other through the two commutators.

7. In a direct-current dynamo, the combination with two commutators, of two sets of armature-coils of substantially the same resistance alternating in position and permanently connected in series through the com mutators.

S. A direct-current dynamo having an armature provided with a plurality of sets of coils of substantially equal resistance alternating in position and permanently connected in series with the external circuit.

9. A direct-current dynamo having an an mature provided with coils differing in number from the field-magnet poles and all of substantially the same resistance, said coils being arranged in sets alternating in position and permanently connected in series with the external circuit.

10. A direct-current dynamo having an armature provided with a greater number of coils than the field-magnet has poles and all of substantially the same resistance, said coils being connected in alternately-arranged parts to form a plurality of sets, and said sets being permanentlyconnected to the external circuit in series.

In testimony whereof I have hereunto subscribed my name this 31 st day of August, A. D. 1895.

BENJ. G. LAMME.

\Vitnesscs:

WEsLnY G. CARR, I-IUBERT C. TONER. 

